<template>
  <div class="todo-container">
    <div class="todo-wrap">
      <TodoHeader :addTodo="addTodo"/>
      <TodoList :todos="todos" :deleteTodo="deleteTodo"/>
      <todo-footer
        :todos="todos"
        :deleteCompleteTodos="deleteCompleteTodos"
        :selectAllTodos="selectAllTodos"
      />
    </div>
  </div>
</template>

<script>
import TodoHeader from "./components/TodoHeader.vue";
import TodoFooter from "./components/TodoFooter.vue";
import TodoList from "./components/TodoList.vue";
export default {
  data() {
    return {
      //从localstorage读取todos
      todos: JSON.parse(window.localStorage.getItem("todos_key") || "[]")
    };
  },
  methods: {
    addTodo(todo) {
      this.todos.unshift(todo);
    },
    deleteTodo(index) {
      this.todos.splice(index, 1);
    },
    //删除所有选中的todo
    deleteCompleteTodos() {
      this.todos = this.todos.filter(todo => !todo.complete);
    },
    //全选，全不选
    selectAllTodos(check) {
      this.todos.forEach(todo => (todo.complete = check));
    }
  },
  watch: {
    //深度监视
    todos: {
      deep: true, //深度监视
      handler: function(Value) {
        //将todos最新的值的json数据保存到保存到localStorage
        window.localStorage.setItem("todos_key", JSON.stringify(Value));
      }
    }
  },

  components: {
    TodoHeader,
    TodoList,
    TodoFooter
  }
};
</script>


<style>
/*app*/
.todo-container {
  width: 600px;
  margin: 0 auto;
}
.todo-container .todo-wrap {
  padding: 10px;
  border: 1px solid #ddd;
  border-radius: 5px;
}
</style>
